1. Field of the Invention
The present invention relates to an apparatus used in electron beam lithography, and more particularly, to a wafer-scale microcolumn array using a low temperature co-fired ceramic (LTCC) substrate.
2. Description of the Related Art
An electron beam microcolumn (hereinafter, referred to as a microcolumn) used for minutely focusing an electron beam was first introduced at the end of the 1980s. The microcolumn has advantages of small size, high resolution, and low production cost. The microcolumn has been applied to various fields, such as electron beam lithography, etc.
In general, the microcolumn includes an electron emission source, silicon electrostatic lenses, more than one octa-electrode electrostatic beam deflector, etc. The silicon electrostatic lens is a thin silicon film having holes of several μm to hundreds of μm in diameter formed by a typical MEMS (micro electro mechanical systems) process. The silicon electrostatic lens has high electric conductivity obtained, for example, by injecting boron impurities thereinto. The electrostatic lens has various apertures. The electrostatic lens performs as an electro-optical lenses, which restricts an electron beam emitted from an electron emission source and electrostatically converges the electron beam by an external voltage source. One octa-electrode electrostatic beam deflector has eight polygonal electrodes formed in a radial shape by, for example, reactive ion etching (RIE) of silicon. The electrostatic beam deflector bends electron beams passing through the center of the deflector using an electrostatic force generated by an externally applied voltage. The microcolumn has an advantage of low power consumption.
Meanwhile, if microcolumns are arrayed on a wafer-scale basis, a huge amount of wafers can be processed by a semiconductor lithography process in units of time. In general, the array of microcolumns is performed by wafer-scale arrangement of separately produced unit microcolumns, wafer-scale arrangement of monolithic microcolumns, or synchronous arrangement of a wafer-scale microcolumn. A method of forming wirings between a lens and a beam deflector using a semiconductor manufacturing process has been proposed in manufacturing a wafer-scale microcolumn. However, the use of the semiconductor manufacturing process has drawbacks in that the manufacturing process becomes too complicated and expensive.